Continually impressed by the @pixelfed spam detection system (Autospam)
It keeps getting better with every detection (that leads to action), it was pretty much useless before I added the machine learning logic as most of them would work around the previous constraints
I'm proud of the way I implemented it too, it doesn't get in the way, or is even noticeable in the moderation process!
It simply trains the dataset based on the action you take, it's almost magic.